Two different nucleotide substitutions of APC gene in a family with familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is an autosomal dominant syndrome leading to colorectal cancer. This disease appears as a result of germline mutation in adenomatous polyposis coli (APC) gene. The aim of the present study is to report the association between two different nucleotide substitutions detected in a family with FAP. In the proband, p.His1172Gln (c.3516delT) was detected in exon 15 of the APC gene. Furthermore, p.His1172Gln (c.3516delT) and, in addition to this mutation, p.Met1413Val (c.4237 A > G) were detected in exon 15 in both daughters of the proband. However, we believe that single nucleotide change in codon 1413 may be a polymorphic variant and deletion T in codon 1172 of APC gene is associated with FAP, attenuated FAP and extracolonic FAP involvement. Along with common use of genetic tests in the clinical practice, genotype-phenotype correlation may be recognized better and useful for early diagnosis and prevention of familial cancer syndromes.